hpinson wrote:I know I started this thread, but...
I just want to make sure that everyone understands that my own conclusions are that there are very questionable benefits to this approach... while siliconizing the bag results in a nice tight bag and bellows, longevity is questionable, and toxicity and reed degradation may be issues.
Hi Harlow, all...
First - sorry to nitpick but this has been bugging me for months and I just can't help myself... It's silicone
, i.e. think cosmetic surgery, not siliCON which is a semiconducting metal used in electronic components. Possibly 3M is misspelling it in their product name but that would just be daft.
Andreas Rogge used to use a silicone-based clear sealant inside his bags; I don't know if he still does.
I don't think there is a real toxicity issue, insofar as nothing from inside the bag should be finding its way into your body. The toxic ingredient in these sealants is mostly the fungicide, which as previously mentioned can be avoided by choosing a product without it. You guys use caulking in your homes, don't you? More of a worry in the kitchen and bathroom than in the bag, and the stuff is sold for use in kitchens... some types even for aquaria. Similarly I fail to see a problem with the reeds, at least after the initial cure period where acetic acid (i.e. vinegar) is off-gassed. Longevity for bags seems fine, at least based on anecdotal reports and my own previous experience with Rogge bags.
Better to obtain proper leather; chrome tanned elk hide that needs minimal or no seasoning, or quality upholstory leather plus beeswax + oil (neatsfoot or olive per preferance, rosin) seasoning; or go with an airtight synthetic like Naugahyde or the more durable/costly and less stretchy Hypalon. And, use a bag cover.
Obtaining the proper leather seems difficult right now in the US. Several current sources have been suggested, and they have been discouragingly unresponsive, at least to my queries. Leather Factory / Tandy does not usually have the "right" stuff, though occasionally something suitable is in stock.
Perhaps there is an international bagpipe leather cartel. How do I join?
I learned a lot in the process.
Finding the "right stuff" in the pipes business often takes a lot of digging. I see little advantage, and much to dislike, in bag covers, but then again I don't tend to sweat profusely when playing pipes (preferring lighter reeds). For those who do I can see a potential problem with suede-side-out leather bags. Bonding/delamination can be at least as big a problem with wax/oil-based treatments as with silicone - in fact I would say greater, as the silicone doesn't tend to creep with time and temperature. Most attempts at oil/wax treatments which I have encountered have yielded results that I found unsatisfactory (I refer here to the end result of _other_ peoples' treatments, including experienced makers), but that doesn't mean that it is not possible to get good results.
The "good" results I recall encountering are (not necessarily in this order, and in my own opinion):
(formerly) Dominion Leather as used by L&M, which is chrome-tanned and then treated with a non-oily/non-waxy polymer coating or some kind (proprietary);
Rogge bags with some silicone-based coating on the inside (possibly applied after stitching, it was not really obvious);
MacHarg bags, which were once I believe made with Dominion Leather (same coating) but are now made with something else and rivited;
Chrome-tanned leather coated with Evo-stick brand contact adhesive thinned 1:1 with thinner/solvent (the old formula, no longer available).
I have also used bags from another fellow in the North of Ireland which were reasonably airtight without further seasoning, but it is not apparent whether the leather has a coating; these are perhaps not quite as airtight as the varieties above.
I have heard of good results achieved with pour-in thin latex, but it is important to remove all stocks etc. before adding any sealant, and the latex will stick to itself unless is is powdered/chalked afterwards, which is probably bad for the reeds. This last treatment is one that has received bad press online before, I cannot personally recommend it.
I don't think any of these approaches are really sufficient for bellows though, since the nature of bellows is such that there are tight folds and places where the leather is constantly rubbing together in service. That would tend to degrade any coating over time. The answer for bellows seems either fairly thick, airtight leather from the start, or a 2-ply leather gusset (with a glue layer in between that both seals the leather and forms an additional barrier). I think the latter is more common.